摘要
以野牛草为试材，在颖苞解剖结构观察以及吸胀测定的基础上进行了剥除颖苞后的０．２％ＫＮＯ３低温预处理和ＧＡ３、乙烯利两种激素前处理。前处理后在８０℃恒温和３０～１０℃变温条件下测定种子发芽率及淀粉酶活性。结果表明，野牛草种子是综合休眠型；聚合颖苞的吸水通常在置床后７２小时只能达到颖果干重的２６％，而剥去颖苞的颖果在置床后３４小时吸水量可达该种子萌发水分含量的下限即４０％；连种单位中的颖果之间没有相互抑制作用，各自的休眠与萌发是独立的。在０．２％ＫＮＯ３溶液中预冷一周，然后在１０～３０℃变温条件下萌发，其发芽率可达８５％。１５０ｍｐ／Ｌ的ＧＡ３外源激素处理可以代替ＫＮＯ３冷冻预处理。种子萌发过程中β－淀粉酶与α－淀粉酶有协同作用。
Anatomy structure and imbibition of buffalograss [Buchloe dactyloides (Nutt) Engelm] seeds with the hard bracts removed or unremoved were studied. Thereafter the caryopsis were treated with 0.2% KNO3 at 0～4℃ for a week, or with 150mg/L GA3 or 800mg/L ethephon respectively. Both treated and untreated caryopsis were then germinated at constant temperature of 30℃ or at alternate temperature of 30～10℃ in a germinating chamber. The seed germinating rate was calculated every day for 28 days. The amylase activity of germinating seeds and seedlings were tested one and two weeks respectively after they were set on the paper beds. Present study indicates that dormancy of buffalograss seeds were controlled by syndrome factors. The hard bract restricts water imbibition to 26% of dry weight of caryopsis against the germinating requisition of 40%.The synaptosperms seem not interact but differ in dormant degree. The seed dormancy could be broken by removing the hard bract and pretreating the caryopsis in 0.2% KNO3 solution at 0～4℃, so that the germinating rate reached 85% in two weeks.Exogenous GA3 and ethephon could partialy replace the pretreatment by activating the amylases. It is proPOsed th.at the α-amylase activity was directly resPOnsible to the seed germination while the β-amylase was effective only when sufficient α-amylase activity co-existed.
出处
《园艺学报》
CAS
CSCD
北大核心
1995年第4期377-380,共4页
Acta Horticulturae Sinica
